Leases - Components of Lease Expense and Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Leases [Abstract]
Operating lease expense	$ 250	$ 283	$ 488	$ 854
Finance lease expense:
Amortization of right-of-use assets	4	4	7	9
Interest on lease liabilities	3	5	6	9
Total finance lease expense	7	9	13	18
Short-term lease expense	61	54	55	86
Total lease expense	318	346	556	958
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	394	1,411	727	1,024
Operating cash flows from finance leases	43	5	53	9
Financing cash flows from finance leases	$ 3	$ 14	$ 29	$ 51